2 3\ / \l 11 

 mA aj\/aj\ ft sin 4 o) t 



2Tr 



8u 



2-n /iii 



1/2 



2 3 



p _ m A to 



""" ^ 2 yy 



For the steel plowshare, triangular in cross section with u = 4 inches 

 and £=12 inches , one has 



m = i-_ — 



f 2" Ji CO h ] 



^ (0.28 lb/in.^)(0.5)(4 in.) (12 in.) (36 in.) 

 384 in./sec^ 



2 

 = 0.63 lb-sec /in. 



From References 13 and 14 one selects 



A = 0.25 in. 



f = 1,800 rpm or w = 188.5 rad/sec 

 Therefore, 

 p _ (0.63 lb-sec^/in.)(0.25 in.)^(188.5 rad/sec)^(ft/12 in.) 



l-JT 



hp 



500 ft-lb/sec 



For A = 0.375 



P = 14 hp 

 rms 



P = 32 hp 



rms 



I 



59 



